Device for charging a bulk material into a container and method for the use thereof

ABSTRACT

The apparatus has a closed housing ( 4, 29 ), one side of the housing ( 4, 29 ) being the filling side ( 13 ), which, during filling of the container ( 2 ), is located opposite an introduction opening ( 6 ) provided in said container. The housing ( 4 ) has a filling tube ( 3, 33 ) passing through it axially in relation to the axis of the introduction opening ( 6 ), said filling tube, on the filling side ( 13 ), protruding to such an extent that, in the filling position, projects into the introduction opening ( 6 ). The interior of the housing ( 4, 29 ) is connected to an external arrangement for extracting dust by suction, and the filling side ( 13 ) has an air-inlet opening.  
     In respect of the process, for the purpose of filling the container ( 2 ), the filling side ( 13 ) of the housing ( 4 ) is positioned above the introduction opening ( 6 ) of the container ( 2 ) such that a gap (a) is produced between the filling side ( 13 ) and the introduction opening ( 6 ), and the arrangement for extracting dust by suction is set in operation at least during filling of the container ( 2 ).

TECHNICAL FIELD

[0001] The invention relates to an apparatus for introducing bulk goodsinto a container, the apparatus having an arrangement for extractingdust, which can pass into the surroundings during filling of thecontainer, by suction. The invention also relates to a process for usingan apparatus according to the invention.

PRIOR ART

[0002] Various apparatuses for introducing bulk goods into containersare known from the prior art. Relevant apparatuses in the present caseare those which are suitable for dust-containing bulk goods or for bulkgoods in which dust may be produced, for example, by abrasion duringtransfer.

[0003] Open ventilator cowls, which are arranged above the fillinglocation, are known in general.

[0004] DE 42 11 855 A1 describes an arrangement for loading bulk goods.In one embodiment, a dust-removal nozzle is provided in the region wherethe bulk goods enter the loading arrangement. A dust-return line resultsin dust-laden air being returned from the container which is to beloaded into the loading hopper of the loading arrangement. Duringoperation of the arrangement, the dust within the loading arrangement isdirected to the dust-removal nozzle by way of the air stream, a negativepressure being present in the interior of the arrangement. Duringloading of the bulk goods, the arrangement is coupled with dust-sealingaction to the container which is to be loaded. In this case, the hoppermouth and the dust-return line are introduced in parallel into theopening of the container which is to be loaded.

[0005] DE 72 18 354 U1 describes a loading arrangement for loading siloswith bulk goods in a dust-free manner. The loading arrangement has afilling tube, of which the bottom end is enclosed by a rubber-coatedloading cone. The loading cone, which is arranged in the form of a ringaround the filling tube, simultaneously serves as a dust-removal nozzle,which is connected functionally to a suction-extraction and dust-removalapparatus via a folding bellows. During the sealing operation, theloading cone is seated firmly, in a dust-sealed manner, in theintroduction hole of the silo.

[0006] The disadvantage here is that it is not possible to prevent atleast some dust from escaping into the surroundings, or relativelyhigh-outlay sealing of the hopper mouth and of the dust-return line inrelation to the opening of the container which is to be loaded isnecessary. It is also disadvantageous that coupling the arrangement andthe dust-return line to the container which is to be loaded results inconnecting forces taking effect, as a result of which it is not possiblefor the net filling quantity to be determined precisely during filling.

DESCRIPTION OF THE INVENTION

[0007] It is thus an object of the invention to specify an apparatus forintroducing bulk goods into a container of the type mentioned in theintroduction which prevents dust from the bulk goods from entering intothe surroundings. It also intended to specify a process for using theapparatus. It is also intended to be possible here for the net fillingquantity to be determined precisely during introduction of the bulkgoods into the container.

[0008] The invention achieves the object in respect of the apparatus bythe features mentioned in the defining part of claim 1. Advantageousdevelopments of the apparatus are defined in subclaims 2 to 6 and areillustrated in more detail hereinbelow together with the description ofthe preferred configuration of the invention, including the drawing.

[0009] The object in respect of the process is achieved by the definingpart of claim 7. An advantageous development of the process is definedin subclaim 8.

[0010] The essence of the invention consists, in particular, in that theapparatus has a housing, of which the interior is connected to anexternal arrangement for extracting dust by suction, in that the sealingtube is mounted within the housing, and in that air-inlet openings areprovided in the housing radially outside the introduction housing of thecontainer which is to be filled.

[0011] In the case of the process-related use of the apparatus forfilling a container with bulk goods, the apparatus, specifically thefilling side of the housing, is positioned above the container, i.e.above the introduction opening of the latter, such that a defined gap isproduced between the housing and the container. In respect of theprocess, it is further the case that the arrangement for extracting dustby suction is set in operation.

[0012] The arrangement for extracting dust by suction produces anegative pressure in the housing of the apparatus, which results in airfrom the surroundings flowing into the housing, by way of the air-inletopenings, on the filling side. A collar is advantageously arranged onthe filling side of the housing, radially outside the introductionopening of the container and the air-inlet openings. In the fillingposition, this collar is intended to project axially beyond the outerborder of the introduction opening. As a result, the air stream isdeflected essentially in a vertical direction and swirling of the air,which possibly results in dust passing into the surroundings, isavoided.

[0013] The air stream flows around the introduction opening of thecontainer in tubular fashion. This results in all the dust particles andgases escaping from the container during filling of the latter beingentrained. The escape of dust from the gap between the apparatus and theintroduction opening is more or less prevented by the air stream.

[0014] In an advantageous configuration, the filling tube is arrangedsuch that it can easily be removed from the housing. For this purpose,the filling tube is mounted in the housing, and sealed in relation tothe latter, by means of rubber sleeves. This reduces any vibrations inrelation to the apparatus during the bulk-goods transfer. The fillingtube can easily be drawn out of the housing.

[0015] This is advantageous, for example, if the apparatus is to be usedfor transferring different bulk goods, using different filling tubes, atsuccessive points in time. In particular in the case of pharmaceuticalbulk goods, e.g. powder or granules, it is necessary from atechnological point of view for the entire apparatus to be cleanedcyclically. For this purpose, it is necessary for the apparatus,including the filling tube, to be dismantled and fed to a washingapparatus.

[0016] The actual design of the housing with the filling tube andair-guiding means can be varied to a great extent and adapted to thegeometrical and structural conditions.

[0017] When the apparatus is in the rest position, i.e. when there is nocontainer which is to be filled positioned beneath the apparatus, it hasproven advantageous to arrange a protecting means beneath the housingand, in particular, beneath the outlet opening of the filling tube. Thisprevents residues of the bulk goods from trickling accidentally into theopen from the filling tube, or prevents dust deposits from dropping outof the filling tube and contaminating the surroundings.

[0018] The extent to which it is necessary to allow the arrangement forextracting dust by suction to function even when the outlet opening ofthe filling tube is actually closed is determined by the actualtechnological conditions.

[0019] Protecting means which may be used are slide-like, shutter-like,pivoting-plate-like or iris-diaphragm-like means, as are known ingeneral from the prior art. The selection in practice is decisivelyinfluenced by the local conditions. The protecting means isadvantageously mounted in a dedicated housing. When not in use, it canbe retracted into the housing. It is possible here to provide in thehousing special suction slots, by means of which any residues of bulkgoods present are extracted by suction during retraction of theprotecting means.

[0020] The invention is explained in more detail hereinbelow withreference to two exemplary embodiments. In the associated drawing:

[0021]FIG. 1 shows, in respect of exemplary embodiment I, an apparatusaccording to the invention arranged on the ceiling,

[0022]FIG. 2 shows a section through the housing according to FIG. 1,and

[0023]FIG. 3 shows, in respect of exemplary embodiment II, afloor-supported apparatus according to the invention.

[0024] Exemplary Embodiment I

[0025]FIG. 1 shows, in respect of exemplary embodiment I, an apparatusaccording to the invention which is arranged on a ceiling 1.Non-illustrated silos or installations for producing a pharmaceuticalpowder as the bulk goods may be located above the ceiling. This powderis intended to be transferred into the container 2 beneath the ceiling1. In this case, the container 2 is mounted on weighing scales, whichare intended to determine the precise net filling quantity of powder.

[0026] The actual apparatus according to the invention comprises aclosed housing 4 with air-intake tubes 16 and an annular gap 21. Leadingthrough the housing 4 is a filling tube 3, of which the outlet opening 5penetrates into the introduction opening 6 of the container 2.

[0027] The housing 4 is secured on the ceiling 1 via a load-bearingapparatus 7. A slide 8 is arranged, as protecting means, to the side ofthe housing 4 and of the outlet opening 5. In the rest position, whenthere is no container 2 located beneath the filling tube 3, the outletopening 5 may thus be covered from beneath such that the residues ofbulk goods cannot trickle onto the floor from the ceiling tube 3 and thehousing 4 as a whole. The slide 8 can easily be moved beneath thehousing 4 with the filling tube 3.

[0028]FIG. 2 illustrates in more detail the apparatus in the region ofthe housing 4. In this case, chain-dotted lines are used to indicate thecontainer 2 with the introduction opening 6.

[0029] The housing 4 essentially comprises an outer cylinder 11, whichis connected in structural terms to the load-bearing apparatus 7, thetop covering plate 12 and the filling side 13. The filling tube 3 passesthrough the housing 4 centrally from above. In this case, the fillingtube 3 leads, via a guide hopper 14, through the top covering plate 12and passes out of the filling side 13 again at the bottom. The length ofthe filling tube 3 from the outlet on the filling side 13 as far as theoutlet opening 5 is dimensioned such that the air with dust particleswhich escapes from the container 2 during filling, as far as possible,does not swirl up the bulk-goods stream.

[0030] A guide hopper 14 serves as an auxiliary means for introducingthe filling tube 3 into the housing 4 when the filling tube is exchangedor when it is inserted into the housing 4 again following necessarycleaning.

[0031] Located within the housing 4 is a retaining plate 15 which isconcentric with the filling tube 3 and in the outer region of which twomutually opposite air-intake tubes 16 open out and are secured therewith the interposition of rubber sleeves 17. The air-intake tubes 16 areconnected, via the tube elements 10 (FIG. 1), to an arrangement forextracting dust by suction (not illustrated).

[0032] The filling side 13 of the housing 4 is a combination of a bottomcovering plate 18, a rubber sleeve 19 and a flow plate 20.

[0033] The bottom covering plate 18 ensures the necessary mechanicalstability of the filling side 13. The rubber sleeve 19 secures thefilling tube 3 centrally and elastically and seals it at the same time.The flow plate 20 secures the rubber 19 on the bottom covering plate 18and defines, with its outer edge, an annular gap 21 in relation to acollar 22. The collar 22 here is an extension of the outer cylinder 11,which projects axially beyond the introduction opening 6 in thecontainer 2.

[0034] The slide 8 is secured in a housing 9, into which it can beretracted when not in use. In the exemplary embodiment, the housing 9also accommodates tube elements 10 of the apparatus for extracting dustby suction. In this case, the interior of the housing 9 is alsoconnected to the arrangement for extracting dust by suction. Located onthe side from which the slide 8 is moved out of and into the housing 9are suction slots 25, which are likewise connected to the apparatus forextracting dust by suction, and by means of the configuration of whichany residues of bulk goods present on the slide 8 are extracted bysuction when the slide is retracted into the housing 9.

[0035] The process-related use of the apparatus according to theinvention is described in more detail hereinbelow.

[0036] For the purpose of filling with the pharmaceutical powder, thecontainer 2 is positioned axially beneath the filling tube 3. In thiscase, the container 2 is mounted on weighing scales. The arrangement forextracting dust by suction is set in operation, if this has not alreadybeen done. This produces, in the housing 4, a negative pressure which,in turn, produces an air stream through the annular gap 21. Thereafter,the slide 8 is moved from the position beneath the outlet opening 5 ofthe filling tube 3 into the position within the housing 9.

[0037] The container is subsequently raised, via a lifting apparatus(not illustrated), until the spacing a (FIG. 2) between the filling side13 and the introduction opening 6 has assumed a defined magnitude. Atubular vertical air stream 23 forms in this position, said air streamleading from the surroundings by way of the annular gap b, which isformed between the collar 22 and the outer border of the introductionopening 6, via the annular gap 21 into the housing 4 and then into theair-intake tube 16.

[0038] The spacing a is selected in dependence on the annular gap b, andon the rest of the geometrical conditions, such that the air stream 24,which escapes from the container 2 as dust-laden waste air duringfilling, is entrained by the air stream 23 and cannot pass into thesurroundings.

[0039] During filling of the container 2, it is the case, in respect ofthe process, that the abovedescribed weighing scales are used for thepurpose of constantly determining the overall weight of the container 2with the bulk goods and, by subtracting the mass of the container 2,determining the precise net filling quantity of the bulk goods. Theoperation of filling the container 2 is completed when the precisepredetermined net filling quantity has been reached.

[0040] The advantage of the invention consists, in particular, in that,during filling of the container 2 involving a relatively large amount ofdust being developed, no dust passes into the surroundings, and it ispossible for the dust to be reliably disposed of via the apparatus forextracting dust by suction. Furthermore, a predetermined net fillingquantity can be introduced into the container 2 with a high level ofaccuracy. This is possible since there is no force-fitting connectionbetween the container 2 and the apparatus according to the invention.This also means that the container 2 is not subjected to any undefinedvertical forces which are able to falsify the measured values during theweighing operation.

[0041] Exemplary Embodiment II

[0042]FIG. 3 illustrates a floor-supporting apparatus according to theinvention. The support 28 is only indicated in part. Its actual form isadapted to the conditions. Secured on the support 28 are a housing 29, aprotecting means, in the form of a pivoting plate 30, and pipelines 31and 32, which lead to an arrangement for extracting dust by suction. Afilling tube 33 is routed through the housing 29. The specific design ofthe housing 29 is largely similar to the housing 4 in exemplaryembodiment I.

[0043] In FIG. 3, a container 2 with an introduction opening 6 islocated in a lowered position in relation to the housing 29, and theprotecting means 30 is located beneath the housing 29 and the fillingtube 33. In this case, in exemplary embodiment II, the entire plate-likeprotecting means 30 is connected, via the pipeline 32, to thearrangement for extracting dust by suction, and residues of bulk goodsdropping out of the filling tube 33 or of the housing 29 are immediatelyextracted by suction.

[0044] Of course, the invention is not restricted to the exemplaryembodiment described. It is thus readily possible for the individualparts to be adapted in a variable manner to the local conditions.

1. An apparatus for introducing bulk goods into a container (2),comprising an external arrangement for extracting dust by suction, aclosed housing (4, 29), of which the interior is connected to thearrangement for extracting dust by suction and which has a filling side(13) which, during filling of the container (2), is located opposite anintroduction opening (6) provided in said container, also comprising afilling tube (3, 33), which passes through the housing (4) axially inrelation to the axis of the introduction opening (6) and protrudes tosuch an extent that, in the filling position, it projects into theintroduction opening (6), and further comprising an air-inlet opening onthe filling side (13), wherein the air-inlet openings are arrangedradially outside the introduction opening (6).
 2. The apparatus asclaimed in claim 1, wherein the air-inlet openings are designed in theform of an annular gap (21).
 3. The apparatus as claimed in claim 1 or2, wherein provided radially outside the air-inlet openings, on thefilling side (13) of the housing (4), is a collar (22) which, in thefilling position, projects axially beyond the outer border of theintroduction opening (6).
 4. The apparatus as claimed in one of claims 1to 3, wherein the filling tube (3, 33) is at least partially secured andsealing in the housing (4, 29) by means of elastic seals.
 5. Theapparatus as claimed in one of claims 1 to 4, wherein provided beneaththe housing (4, 29) is a protecting means which, in the rest position,when there is no container (2) located beneath the apparatus, covers atleast the outlet opening (5) of the filling tube (3, 33).
 6. Theapparatus as claimed in one of claims 1 to 5, wherein provided beneaththe housing (4, 29) is a weighing apparatus, on which the container (2)may be mounted.
 7. A process for using an apparatus as claimed in one ofclaims 1 to 6, wherein, for the purpose of filling the container (2),the filling side (13) of the housing (4) is positioned above theintroduction opening (6) of the container (2) such that a gap (a) isproduced between the filling side (13) and the introduction opening (6),and wherein the arrangement for extracting dust by suction is set inoperation at least during filling of the container (2).
 8. The processfor using an apparatus as claimed in claim 7, wherein the net fillingquantity of the container (2) is determined by means of the weighingapparatus at least during filling of the container (2).